This is a reorganization of the publications on my cv, organized by topic. An overview of my research is also available. My research in theoretical particle physics falls into two main categories:

- Collider Physics and Quantum Chromodynamics
- Theoretical Frameworks Beyond the Standard Model

In addition, I have studied Little Higgs/Composite Higgs Theories, The LHC Inverse Problem, and taken a few Adventures in Gravity. The articles below are listed in reverse chronological order by category, and those marked with a are recommended starting points to learn more about my work.

Machine learning has impacted many scientific fields, and particle physics is no exception. In my research, I aim to enhance the search for new phenomena at colliders by merging the performance of deep learning algorithms with the robustness of “deep thinking” approaches.

**The Metric Space of Collider Events**.

Patrick T. Komiske, Eric M. Metodiev, and Jesse Thaler.

Phys. Rev. Lett. 123:041801 (2019) (Viewpoint), arXiv:1902.02346.

**Energy Flow Networks: Deep Sets for Particle Jets**.

Patrick T. Komiske, Eric M. Metodiev, and Jesse Thaler.

JHEP 1901:121 (2019), arXiv:1810.05165.

**On the Topic of Jets: Disentangling Quarks and Gluons at Colliders**.

Eric M. Metodiev and Jesse Thaler.

Phys. Rev. Lett. 120:241602 (2018) (Synopsis), arXiv:1802.00008.

**Classification Without Labels: Learning from Mixed Samples in High Energy Physics**.

Eric M. Metodiev, Benjamin Nachman, and Jesse Thaler.

JHEP 1710:174 (2017), arXiv:1708.02949.

Jets are collimated sprays of particles arising from the fragmentation of short-distance quarks and gluons. In traditional collider studies, these jets are reconstructed using jet algorithms, which assign clusters of particles to jet four-vectors. I have shown that the substructure of jets can provide valuable information about the underlying short-distance physics. In extreme cases, physics that would otherwise be unobservable using traditional jet algorithms can be made prominent through jet substructure techniques.

**An Operational Definition of Quark and Gluon Jets**.

Patrick T. Komiske, Eric M. Metodiev, and Jesse Thaler.

JHEP 1811:059 (2018), arXiv:1809.01140.

**Recursive Soft Drop**.

Frédéric A. Dreyer, Lina Necib, Gregory Soyez, and Jesse Thaler.

JHEP 06:093 (2018), arXiv:1804.03657.

**Energy Flow Polynomials: A Complete Linear Basis for Jet Substructure**.

Patrick T. Komiske, Eric M. Metodiev, and Jesse Thaler.

JHEP 1804:013 (2018), arXiv:1712.07124.

**The Importance of Calorimetry for Highly-Boosted Jet Substructure**.

Evan Coleman, Marat Freytsis, Andreas Hinzmann, Meenakshi Narain, Jesse Thaler, Nhan Tran, and Caterina Vernieri.

JINST 13:T01003 (2018), arXiv:1709.08705.

**Systematics of Quark/Gluon Tagging**.

Philippe Gras, Stefan Höche, Deepak Kar, Andrew Larkoski, Leif Lönnblad, Simon Plätzer, Andrzej Siódmok, Peter Skands, Gregory Soyez, and Jesse Thaler.

JHEP 1707:091 (2017), arXiv:1704.03878.

**New Angles on Energy Correlation Functions**.

Ian Moult, Lina Necib, and Jesse Thaler.

JHEP 1612:153 (2016), arXiv:1609.07483.

**Resurrecting the Dead Cone**.

Fabio Maltoni, Michele Selvaggi, and Jesse Thaler.

Phys. Rev. D94:054015 (2016), arXiv:1606.03449.

**Gaining (Mutual) Information about Quark/Gluon Discrimination**.

Andrew J. Larkoski, Jesse Thaler, and Wouter J. Waalewijn.

JHEP 1411:129 (2014), arXiv:1408.3122.

**Aspects of Jets at 100 TeV.**

Andrew J. Larkoski and Jesse Thaler.

Phys. Rev. D90:034010 (2014), arXiv:1406.7011.

**Soft Drop**.

Andrew J. Larkoski, Simone Marzani, Gregory Soyez, and Jesse Thaler.

JHEP 1405:146 (2014), arXiv:1402.2657.

**Energy Correlation Functions for Jet Substructure**.

Andrew J. Larkoski, Gavin P. Salam, and Jesse Thaler.

JHEP 1306:108 (2013), arXiv:1305.0007.

**Maximizing Boosted Top Identification by Minimizing N-subjettiness**.

Jesse Thaler and Ken Van Tilburg.

JHEP 1202:093 (2012), arXiv:1108.2701.

**Identifying Boosted Objects with N-subjettiness**.

Jesse Thaler and Ken Van Tilburg.

JHEP 1103:015 (2011), arXiv:1011.2268.

**Strategies to Identify Boosted Tops**.

Jesse Thaler and Lian-Tao Wang.

JHEP 0807:092 (2008), arXiv:0806.0023.

Along with the rise of jet substructure tools, there has been an increased focus on using (non)perturbative QCD methods to predict the properties of jets. In the past, QCD calculations focused on “infrared and collinear safe” (IRC safe) observables which can be calculated order by order in perturbation theory. Now, the calculational toolbox has expanded to include IRC unsafe observables—such as track-based observables and ratio observables—by using new analytic techniques.

**Photon Isolation and Jet Substructure**.

Zachary Hall and Jesse Thaler.

JHEP 1809:164 (2018), arXiv:1805.11622.

**Aspects of Track-Assisted Mass**.

Benjamin T. Elder and Jesse Thaler.

JHEP 1903:104 (2019), arXiv:1805.11109.

**Casimir Meets Poisson: Improved Quark/Gluon Discrimination with Counting Observables**.

Christopher Frye, Andrew J. Larkoski, Jesse Thaler, and Kevin Zhou.

JHEP 1709:085 (2017), arXiv:1704.06266.

**Generalized Fragmentation Functions for Fractal Jet Observables**.

Benjamin T. Elder, Massimiliano Procura, Jesse Thaler, Wouter J. Waalewijn, and Kevin Zhou.

JHEP 1706:085 (2017), arXiv:1704.05456.

**Sudakov Safety in Perturbative QCD**.

Andrew J. Larkoski, Simone Marzani, and Jesse Thaler.

Phys. Rev. D91:111501 (2015), arXiv:1502.01719.

**The First Calculation of Fractional Jets**.

Daniele Bertolini, Jesse Thaler, and Jonathan R. Walsh.

JHEP 1505:008 (2015), arXiv:1501.01965.

**Jet Shapes with the Broadening Axis**.

Andrew J. Larkoski, Duff Neill, and Jesse Thaler.

JHEP 1404:017 (2014), arXiv:1401.2158.

**Unsafe but Calculable: Ratios of Angularities in Perturbative QCD**.

Andrew J. Larkoski and Jesse Thaler.

JHEP 1309:137 (2013), arXiv:1307.1699.

**Calculating Track Thrust with Track Functions**.

Hsi-Ming Chang, Massimiliano Procura, Jesse Thaler, and Wouter J. Waalewijn.

Phys. Rev. D88:034030 (2013), arXiv:1306.6630.

**Calculating Track-Based Observables for the LHC**.

Hsi-Ming Chang, Massimiliano Procura, Jesse Thaler, and Wouter J. Waalewijn.

Phys. Rev. Lett. 111:102002 (2013), arXiv:1303.6637.

**Power Corrections to Event Shapes with Mass-Dependent Operators**.

Vicent Mateu, Iain W. Stewart, and Jesse Thaler.

Phys. Rev. D87:014025 (2013), arXiv:1209.3781.

**Precision Jet Substructure from Boosted Event Shapes**.

Ilya Feige, Matthew D. Schwartz, Iain W. Stewart, and Jesse Thaler.

Phys. Rev. Lett. 109:092001 (2012), arXiv:1204.3898.

The boundary between jets and jet substructure has blurred over the years, and will continue to do so. The following techniques are primarily aimed applicable at identifying jets themselves, but take lessons learned from jet substructure studies to study the superstructure of events.

**Disentangling Heavy Flavor at Colliders**.

Philip Ilten, Nicholas L. Rodd, Jesse Thaler, and Mike Williams.

Phys. Rev. D96:054019 (2017), arXiv:1702.02947.

**Resolving Boosted Jets with XCone**.

Jesse Thaler and Thomas F. Wilkason.

JHEP 1512:051 (2015), arXiv:1508.01518.

**XCone: N-jettiness as an Exclusive Cone Jet Algorithm**.

Iain W. Stewart, Frank J. Tackmann, Jesse Thaler, Christopher K. Vermilion, and Thomas F. Wilkason.

JHEP 1511:072 (2015), arXiv:1508.01516.

**Separated at Birth: Jet Maximization, Axis Minimization, and Stable Cone Finding**.

Jesse Thaler.

Phys. Rev. D92:074001 (2015), arXiv:1506.07876.

**Jet Observables Without Jet Algorithms**.

Daniele Bertolini, Tucker Chan, and Jesse Thaler.

JHEP 1404:013 (2014), arXiv:1310.7584.

**Jets with Variable R**.

David Krohn, Jesse Thaler, and Lian-Tao Wang.

JHEP 0906:059 (2009), arXiv:0903.0392.

**Sorting Out Quenched Jets**.

Jasmine Brewer, José Guilherme Milhano, and Jesse Thaler.

arXiv:1812.05111.

**Searching in CMS Open Data for Dimuon Resonances with Substantial Transverse Momentum**.

Cari Cesarotti, Yotam Soreq, Matthew J. Strassler, Jesse Thaler, and Wei Xue.

Phys. Rev. D100:015021 (2019), arXiv:1902.04222.

In November 2014, the CMS experiment at the Large Hadron Collider released the first batch of public collider data. I am involved in the MIT Open Data (MOD) project to apply novel data analysis techniques to this valuable data set.

**Jet Substructure Studies with CMS Open Data**.

Aashish Tripathee, Wei Xue, Andrew Larkoski, Simone Marzani, and Jesse Thaler.

Phys. Rev. D96:074003 (2017), arXiv:1704.05842.

**Exposing the QCD Splitting Function with CMS Open Data**.

Andrew Larkoski, Simone Marzani, Jesse Thaler, Aashish Tripathee, and Wei Xue.

Phys. Rev. Lett. 119:132003 (2017), arXiv:1704.05066.

I work on new ways to probe ultralight axion dark matter (not to be confused with the axion portal below), which requires very different detection techniques than heavy-particle dark matter.

**Searching for Axion Dark Matter with Birefringent Cavities**.

Hongwan Liu, Brodi D. Elwood, Matthew Evans, and Jesse Thaler.

Phys. Rev. D100:023548 (2019), arXiv:1809.01656.

**Broadband and Resonant Approaches to Axion Dark Matter Detection**.

Yonatan Kahn, Benjamin R. Safdi, and Jesse Thaler.

Phys. Rev. Lett. 117:141801 (2016), arXiv:1602.01086.

Dark matter is five times more abundant than ordinary (baryonic) matter, a fact that is firmly established through a variety of gravitational tests. A key question is whether dark matter might have other interactions with the standard model beyond gravity. One possibility is that dark matter experiences dark forces, which are only feebly felt by the standard model. A new generation of experiments is being pursued to find evidence for such dark forces, and I am involved in an MIT-led proposal called DarkLight to use the energy-recovery linac at Jefferson lab to search for a “dark photon”.

**Inclusive Dark Photon Search at LHCb**.

Philip Ilten, Yotam Soreq, Jesse Thaler, Mike Williams, and Wei Xue.

Phys. Rev. Lett. 116:251803 (2016), arXiv:1603.08926.

**Dark Photons from Charm Mesons at LHCb**.

Philip Ilten, Jesse Thaler, Mike Williams, and Wei Xue.

Phys. Rev. D92:115017 (2015), arXiv:1509.06765.

**DAEdALUS and Dark Matter Detection**.

Yonatan Kahn, Gordan Krnjaic, Jesse Thaler, and Matthew Toups.

Phys. Rev. D91:055006 (2015), arXiv:1411.1055.

**Searching for an Invisible A' Vector Boson with DarkLight**.

Yonatan Kahn and Jesse Thaler.

Phys. Rev. D86:115012 (2012), arXiv:1209.0777.

**Dark Force Detection in Low Energy e-p Collisions.**

Marat Freytsis, Grigory Ovanesyan, and Jesse Thaler.

JHEP 1001:111 (2010), arXiv:0909.2862.

Dark forces are part of a large paradigm of dark portals connecting visible and hidden sectors of nature. I developed the idea of an “axion portal”, where dark matter and ordinary matter interact via a light pseudoscalar particle. While dark matter itself is quite difficult to probe in these scenarios, the axion leaves distinction signatures in collider experiments. Axion-like states and stable dark matter arise quite generically in supersymmetric hidden sectors, which can have an interesting effect on the measured cosmic ray spectrum.

**Dark Matter from Dynamical SUSY Breaking**.

JiJi Fan, Jesse Thaler, and Lian-Tao Wang.

JHEP 1006:045 (2010), arXiv:1004.0008.

**Cosmic Signals from the Hidden Sector.**

Jeremy Mardon, Yasunori Nomura, and Jesse Thaler.

Phys. Rev. D80:035013 (2009), arXiv:0905.3749.

**Constraining the Axion Portal with B → K l+ l-**.

Marat Freytsis, Zoltan Ligeti, and Jesse Thaler.

Phys. Rev. D81:034001 (2010), arXiv:0911.5355.

**Dark Matter Signals from Cascade Annihilations**.

Jeremy Mardon, Yasunori Nomura, Daniel Stolarski, and Jesse Thaler.

JCAP 0905:016 (2009), arXiv:0901.2926.

**Dark Matter through the Axion Portal**.

Yasunori Nomura and Jesse Thaler.

Phys. Rev. D79:075008 (2009), arXiv:0810.5397.

One of key questions about dark matter is how it is produced in the early universe. In the standard weakly-interacting massive particle (WIMP) paradigm, dark matter is kept in thermal equilibrium when the universe is hot and dense, and once dark matter become sufficiently dilute from the expansion of the universe, it “freezes out” and the relic cold dark matter is what we observe today. However, there are many deviations from this standard paradigm, which lead to different predictions for the interactions of dark matter we can observe in direct and indirect detection experiments.

**Dark Matter, Shared Asymmetries, and Galactic Gamma Ray Signals**.

Nayara Fonseca, Lina Necib, and Jesse Thaler.

JCAP 1602:052 (2016), arXiv:1507.08295.

**(In)direct Detection of Boosted Dark Matter**.

Kaustubh Agashe, Yanou Cui, Lina Necib, and Jesse Thaler.

JCAP 1410:062 (2014), arXiv:1405.7370.

**Multiple Gamma Lines from Semi-Annihilation**.

Francesco D'Eramo, Matthew McCullough, and Jesse Thaler.

JCAP 1304:030 (2013), arXiv:1210.7817.

**Dark Matter Assimilation into the Baryon Asymmetry**.

Francesco D'Eramo, Lin Fei, and Jesse Thaler.

JCAP 1203:010 (2012), arXiv:1111.5615.

**Semi-annihilation of Dark Matter**.

Francesco D'Eramo and Jesse Thaler.

JHEP 1006:109 (2010), arXiv:1003.5912.

**Navigating Collinear Superspace**.

Timothy Cohen, Gilly Elor, Andrew J. Larkoski, and Jesse Thaler.

arXiv:1810.11032.

**TASI 2012: Super-Tricks for Superspace**.

Daniele Bertolini, Jesse Thaler, and Zachary Thomas.

arXiv:1302.6229.

Supersymmetry (SUSY) is well-motivation extension of space-time symmetry, with unique predictions for collider experiments like the LHC. SUSY is particularly interest in the context of cosmology, since the geometry of the universe is de Sitter (dS), but supergravity (SUGRA) retains a memory of an underlying anti-de Sitter (AdS) algebra. I have studied implications this AdS structure, in particular showing that the phenomenon known as “anomaly-mediatied SUSY breaking” does not actually break SUSY, but is rather a SUSY-preserving effect in anti-de Sitter space.

**Cosmology with Orthogonal Nilpotent Superfields**.

Sergio Ferrara, Renata Kallosh, and Jesse Thaler.

Phys. Rev. D93:043516 (2016), arXiv:1512.00545.

**The Goldstone and Goldstino of Supersymmetric Inflation**.

Yonatan Kahn, Daniel A. Roberts, and Jesse Thaler.

JHEP 1510:001 (2015), arXiv:1504.05958.

**Anomaly Mediation from Unbroken Supergravity**.

Francesco D'Eramo, Jesse Thaler, and Zachary Thomas.

JHEP 1309:125 (2013), arXiv:1307.3251.

**The Two Faces of Anomaly Mediation**.

Francesco D'Eramo, Jesse Thaler, and Zachary Thomas.

JHEP 1206:151 (2012), arXiv:1202.1280.

**Supergravity Computations without Gravity Complications**.

Clifford Cheung, Francesco D'Eramo, and Jesse Thaler.

Phys. Rev. D84:085012 (2011), arXiv:1104.2598.

If SUSY is symmetry of nature, then it must be spontaneously broken. However, very little is known about the dynamics of SUSY breaking, and it is possible (even likely?) that SUSY is broken independently by multiple sectors. In the familiar case where SUSY is broken by a single sector, this gives rise to a single goldstino (a Nambu-Goldstone fermion from SUSY breaking) which is eaten to form the longitudinal components of the gravitino. But if there are multiple sectors that break SUSY, then there is a corresponding multiplicity of “goldstini”, which can affect collider physics and cosmology.

**Visible Supersymmetry Breaking and an Invisible Higgs**.

Daniele Bertolini, Keith Rehermann, and Jesse Thaler.

JHEP 1204:130 (2012), arXiv:1111.0628.

**The Spectrum of Goldstini and Modulini**.

Clifford Cheung, Francesco D'Eramo, and Jesse Thaler.

JHEP 1108:115 (2011), arXiv:1104.2600.

**Goldstini Can Give the Higgs a Boost**.

Jesse Thaler and Zachary Thomas.

JHEP 1107:060 (2011), arXiv:1103.1631.

**A Definitive Signal of Multiple Supersymmetry Breaking**.

Clifford Cheung, Jeremy Mardon, Yasunori Nomura, and Jesse Thaler.

JHEP 1007:035 (2010), arXiv:1004.4637.

**Goldstini**.

Clifford Cheung, Yasunori Nomura, and Jesse Thaler.

JHEP 1003:073 (2010), arXiv:1002.1967.

In particle physics, the principle of naturalness states that measured parameters should be closely related to fundamental parameters. Unnatural theories exhibit delicate cancelations between fundamental parameters to yield anomalously small measured parameters. While naturalness is not a sacred principle in particle physics, it is the basis for much theoretical speculation. Naturalness features prominently in supersymmetric scenarios, but interesting theoretical ideas can arise if naturalness is abandoned completely or taken to logical extremes.

**Auxiliary Gauge Mediation: A New Route to Mini-Split Supersymmetry**.

Yonatan Kahn, Matthew McCullough, and Jesse Thaler.

JHEP 1311:161 (2013), arXiv:1308.3490.

**Flavor Mediation Delivers Natural SUSY**.

Nathaniel Craig, Matthew McCullough, and Jesse Thaler.

JHEP 1206:046 (2012), arXiv:1203.1622.

**The New Flavor of Higgsed Gauge Mediation**.

Nathaniel Craig, Matthew McCullough, and Jesse Thaler.

JHEP 1203:049 (2012), arXiv:1201.2179.

**A Fat Higgs with a Magnetic Personality**.

Nathaniel Craig, Daniel Stolarski, and Jesse Thaler.

JHEP 1111:145 (2011), arXiv:1106.2164.

**Prospects for Mirage Mediation**.

Aaron Pierce and Jesse Thaler.

JHEP 0609:017 (2006), hep-ph/0604192.

The origin of electroweak symmetry breaking is a key question in and beyond the standard model. In the standard model, the Higgs boson plays a key role in breaking electroweak symmetry, but this is not the only option. Models like technicolor invoke strong dynamics to break electroweak symmetry, and there is an intermediate possibility that strong dynamics yields a composite Higgs boson which subsequently breaks electroweak symmetry at a lower energy. One of the most interesting kinds of composite Higgs theories are “little Higgs” models, which invoke a special pattern of overlapping symmetries.

**The Bestest Little Higgs**.

Martin Schmaltz, Daniel Stolarski, and Jesse Thaler.

JHEP 1009:018 (2010), arXiv:1006.1356.

**Collective Quartics and Dangerous Singlets in Little Higgs.**

Martin Schmaltz and Jesse Thaler.

JHEP 0903:137 (2009), arXiv:0812.2477.

**Little M-theory**.

Hsin-Chia Cheng, Jesse Thaler, and Lian-Tao Wang.

JHEP 0609:003 (2006), hep-ph/0607205.

**The Littlest Higgs in Anti-de Sitter Space**.

Jesse Thaler and Itay Yavin.

JHEP 0508:022 (2005), hep-ph/0501036.

In addition to their phenomenological relevance, little Higgs theories offer an interesting testing ground to study spontaneous symmetry breaking itself. The following theoretical studies are aimed at gaining a better of understanding of the dynamics of composite theories, and the plausibility of various symmetry breaking patterns.

**(Reverse) Engineering Vacuum Alignment**.

Clifford Cheung and Jesse Thaler.

JHEP 0608:016 (2006), hep-ph/0604259.

Motivated in part by compositeness models, I have studied a variety of non-supersymmetric theories that stretch the notions of naturalness. These models have revealed new ways to think about flavor physics, Higgs physics, and dark matter, as well as suggested new ways to search for top partners at the LHC.

**Colorful Twisted Top Partners and Partnerium at the LHC**.

Yevgeny Kats, Matthew McCullough, Gilad Perez, Yotam Soreq, and Jesse Thaler.

JHEP 1706:126 (2017), arXiv:1704.03393.

**Exotic Top Partners and Little Higgs**.

John Kearney, Aaron Pierce, and Jesse Thaler.

JHEP 1310:230 (2013), arXiv:1306.4314.

**Top Partner Probes of Extended Higgs Sectors**.

John Kearney, Aaron Pierce, and Jesse Thaler.

JHEP 1308:130 (2013), arXiv:1304.4233.

**Probing Minimal Flavor Violation at the LHC**.

Yuval Grossman, Yosef Nir, Jesse Thaler, Tomer Volansky, and Jure Zupan.

Phys. Rev. D76:096006 (2007), arXiv:0706.1845.

**Natural Dark Matter from an Unnatural Higgs Boson and New Colored Particles at the TeV Scale**.

Aaron Pierce and Jesse Thaler.

JHEP 0708:026 (2007), hep-ph/0703056.

**Disentangling Dimension Six Operators through Di-Higgs Boson Production**.

Aaron Pierce, Jesse Thaler, and Lian-Tao Wang.

JHEP 0705:070 (2007), hep-ph/0609049.

With all eyes on the Large Hadron Collider (LHC), particle physics is posed to learn what physics lies beyond the standard model. After a discovery of new particles or new phenomena, the next task is to figure out how that discovery fits into a theoretical framework. Over the years it has become clear that very different theoretical models can give rise to very similar LHC signatures, a challenge dubbed the “LHC Inverse Problem”.

**Supermodels for early LHC**.

Christian W. Bauer, Zoltan Ligeti, Martin Schmaltz, Jesse Thaler, and Devin G.E. Walker.

Phys. Lett. B 690:280-288 (2010), arXiv:0909.5213.

**MARMOSET: The Path from LHC Data to the New Standard Model via On-Shell Effective Theories**.

Nima Arkani-Hamed, Bruce Knuteson, Stephen Mrenna, Philip Schuster, Jesse Thaler, Natalia Toro, and Lian-Tao Wang.

hep-ph/0703088.

**Supersymmetry and the LHC Inverse Problem**.

Nima Arkani-Hamed, Gordon L. Kane, Jesse Thaler, and Lian-Tao Wang.

JHEP 0608:070 (2006), hep-ph/0512190.

The excitement surrounding the Large Hadron Collider is focused on the possibility of discovering new physics beyond the standard model. However, in order to discover new physics signals, one must have a thorough understanding of standard model background. The workhorse tools for understanding background processes are parton shower generators, which simulate collider events through a variety of controlled and uncontrolled approximations. The goal of the GenEvA project (GENerate EVents Analytically) is to improve the approximations used in Monte Carlo programs as well as smoothly interpolate between different approximation method to construct as complete a picture of the standard model as possible.

**GenEvA (II): A phase space generator from a reweighted parton shower**.

Christian W. Bauer, Frank J. Tackmann, and Jesse Thaler.

JHEP 0812:011 (2008), arXiv:0801.4028.

**GenEvA (I): A new framework for event generation**.

Christian W. Bauer, Frank J. Tackmann, and Jesse Thaler.

JHEP 0812:010 (2008), arXiv:0801.4026.

Lorentz symmetry is the symmetry between space and time, and it is the basis for all fundamental physics. In particular, the absence of any “luminiferous ether” is well-established, and we know that all particles travel according to relativistic dynamics to an excellent approximation. However, there is still the possibility that Lorentz symmetry is spontaneously broken at low energies, and there are a variety of ongoing searches for this “new ether”, which has subtle effects on standard model properties.

**Spontaneous Lorentz Breaking at High Energies**.

Hsin-Chia Cheng, Markus A. Luty, Shinji Mukohyama, and Jesse Thaler.

JHEP 0605:076 (2006), hep-ph/0603010.

**Neutrino Constraints on Spontaneous Lorentz Violation**.

Yuval Grossman, Can Kilic, Jesse Thaler, and Devin G. E. Walker.

Phys. Rev. D72:125001 (2005), hep-ph/0506216.

**Universal Dynamics of Spontaneous Lorentz Violation and a New Spin-Dependent Inverse-Square Law Force**.

Nima Arkani-Hamed, Hsin-Chia Cheng, Markus A. Luty, and Jesse Thaler.

JHEP 0507:029 (2005), hep-ph/0407034.

One of the most exciting possibilities for the Large Hadron Collider (LHC) is the production of microscopic black holes. This is possible in models of extra dimensions, where the fundamental gravity scale is near the LHC center-of-mass energy. A key question is whether the semi-classical intuition for the black hole production rate is correct in the full quantum picture, and we were able to answer this affirmatively in a simple toy theory.

**Dynamics of black hole formation in an exactly solvable model**.

Antal Jevicki and Jesse Thaler.

Phys. Rev. D66 024041 (2002), hep-th/0203172.